Glossary

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Particulate
1. Fine dust or particles (i.e., smoke).

2. Of or relating to minute discrete particles.

3. A particulate substance.

Particulate Pollution
Pollution made up of small liquid or solid particles suspended in the atmosphere or water supply.

Passive Building Design
Building configurations that take advantage of a natural, renewable resource (like sunlight, cooling breezes, etc.). Passive design strategies typically do not involve any moving part or mechanical processes.

Passive Cooling
Using passive building strategies to relieve the cooling load of a building by capitalizing on such things as predictable summer breezes or by shading windows from direct summer sunlight.

Passive Design
Design that reduces the energy consumption of a building by taking advantage of natural heating, cooling, and lighting.

Passive Solar Design
A type of architecture that uses the inherent characteristics of a building to capture heat and light from the Sun.

Passive Solar Heating
Using the sun's energy (in the form of heat) to diminish a building's heating load, usually through the use of large window areas that permit light penetration upon some massive material to use the material's thermal storage capacity.

Pathogens
Microorganisms (i.e., bacteria, viruses or parasites) that can cause disease in humans, animals and plants.

Performance Period
Period during which performance data is collected for an application for LEED certification.

Permaculture Design
A system of assembling conceptual, material and strategic components in a pattern that functions to benefit life in all forms.

Permeable
Open to passage of fluids or gases.

Pervious Paving
Material that allows water to penetrate to the soil below, thereby decreasing the amount of water needed by the water system.

Pesticide
Any chemical used for killing insects, weeds, etc.

Petroleum
Crude oil or any fraction thereof that is liquid under normal conditions of temperature and pressure. The term includes petroleum-based substances comprising a complex blend of hydrocarbons derived from crude oil through the process of separation, conversion, upgrading and finishing, such as motor fuel, jet oil, lubricants, petroleum solvents and used oil.

pH Scale
A logarithmic scale that is used to measure acidity; 1 is very acidic, 7 is neutral, and 14 is very basic (alkaline).

Photochemical Oxidants
Air pollutants formed by the action of sunlight on oxides of nitrogen and hydrocarbons.

Photochemical Smog
Air pollution caused by chemical reactions of various pollutants emitted in the presence of sunlight.

Photosynthesis
The biological process in chlorophyll-containing cells that transforms sunlight, water, and carbon dioxide into plant matter (or biomass).

Photovoltaics (PV)
The use of semiconductor technology to generate electricity directly from sunlight.

Points
Compliance with each LEED credit earns one or more points toward certification. Compliance with prerequisites is required and does not earn points.

Pollutant
Generally, any substance introduced into the environment that adversely affects the usefulness of a resource or the health of humans, animals, or ecosystems.

Pollution
Generally, the presence of a substance in the environment that, because of its chemical composition or quantity, prevents the functioning of natural processes and produces undesirable environmental and health effects. Under the Clean Water Act, for example, the term has been defined as the man-made or man-induced alteration of the physical, biological, chemical and radiological integrity of water and other media.

Pollution Prevention
1. Techniques that eliminate waste prior to treatment, such as changing ingredients in a chemical reaction.

2. Identifying areas, processes and activities that create excessive waste products or pollutants in order to reduce or prevent them through alteration or elimination of a process.

3. The EPA has initiated a number of voluntary programs in which industrial or commercial "partners" join with the EPA in promoting activities that conserve energy, conserve and protect the water supply, reduce emissions or find ways of utilizing them as energy resources, and reduce the waste stream.

Post-consumer Material
Any household or commercial product that has served its original, intended use.

Post-consumer Recycle Content
A product composition that contains some percentage of material that has been reclaimed from the same or another end use at the end of its former, useful life.

Post-industrial Material
Industrial manufacturing scrap or waste; also called pre-consumer material

Post-industrial Recycle Content
A product composition that contains some percentage of manufacturing waste material that has been reclaimed from a process generating the same or a similar product. Also called pre-consumer recycle content.

Potable Water
Water that is safe to drink.

ppb
Parts per billion.

ppm
Parts per million.

Pre-Consumer Waste
See "post-industrial material."

Precautionary Principle
The principle that advises that, in the face of uncertainty, the best course of action is to assume that a potential problem is real and should be addressed ("better safe than sorry").

Prerequisites
LEED Green Building Rating System component. Compliance is mandatory for achieving certification but does not count toward the accumulation of points.

Pyrolysis
Decomposition of a chemical by extreme heat.